A lithium battery in widespread used as an advanced battery at present comprises a liquid electrolyte containing an organic solvent. It is known that such an organic solvent causes a decomposition reaction by oxidation or reduction on the surface of an electrode active material. Then, this decomposition reaction causes formation of a resistive layer at an interface between an electrode active material and an electrolyte. The resistive layer irreversibly increases with time or by repetition of charge-discharge reaction to irreversibly increase battery resistance. As a result, battery performance lowers to reduce battery life. Furthermore, the aforementioned organic solvent is inflammable and therefore it is very expensive in providing measures for safety.
Consequently, some proposals have been made to develop batteries composed of only a nonflammable solid. A method for manufacturing an all-solid-state lithium battery, for example, disclosed in Japanese Unexamined Patent Publication No. 2000-251938, is characterized in that solid electrolyte powder is interposed between positive and negative electrode active materials containing a solid electrolyte to be sealed after microwave heating. A lithium battery disclosed in Japanese Unexamined Patent Publication No. 2001-126757 is one in which an oxide based inorganic solid electrolyte is interposed between a positive electrode and a negative electrode to be formed by binding electrode active materials with oxide glass.